// SPDX-License-Identifier: GPL-2.0
/*
 * Driver for Intel PMC USB mux control
 *
 * Copyright (C) 2020 Intel Corporation
 * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
 */

#include <linux/acpi.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include <linux/usb/role.h>
#include <linux/usb/typec_mux.h>
#include <linux/usb/typec_dp.h>
#include <linux/usb/typec_tbt.h>

#include <asm/intel_pmc_ipc.h>

#define PMC_USBC_CMD		0xa7

/* "Usage" OOB Message field values */
enum {
	PMC_USB_CONNECT,
	PMC_USB_DISCONNECT,
	PMC_USB_SAFE_MODE,
	PMC_USB_ALT_MODE,
	PMC_USB_DP_HPD,
};

#define PMC_USB_MSG_USB2_PORT_SHIFT	0
#define PMC_USB_MSG_USB3_PORT_SHIFT	4
#define PMC_USB_MSG_UFP_SHIFT		4
#define PMC_USB_MSG_ORI_HSL_SHIFT	5
#define PMC_USB_MSG_ORI_AUX_SHIFT	6

/* Alt Mode Request */
struct altmode_req {
	u8 usage;
	u8 mode_type;
	u8 mode_id;
	u8 reserved;
	u32 mode_data;
} __packed;

#define PMC_USB_MODE_TYPE_SHIFT		4

enum {
	PMC_USB_MODE_TYPE_USB,
	PMC_USB_MODE_TYPE_DP,
	PMC_USB_MODE_TYPE_TBT,
};

/* Common Mode Data bits */
#define PMC_USB_ALTMODE_ACTIVE_CABLE	BIT(2)

#define PMC_USB_ALTMODE_ORI_SHIFT	1
#define PMC_USB_ALTMODE_UFP_SHIFT	3
#define PMC_USB_ALTMODE_ORI_AUX_SHIFT	4
#define PMC_USB_ALTMODE_ORI_HSL_SHIFT	5

/* DP specific Mode Data bits */
#define PMC_USB_ALTMODE_DP_MODE_SHIFT	8

/* TBT specific Mode Data bits */
#define PMC_USB_ALTMODE_TBT_TYPE	BIT(17)
#define PMC_USB_ALTMODE_CABLE_TYPE	BIT(18)
#define PMC_USB_ALTMODE_ACTIVE_LINK	BIT(20)
#define PMC_USB_ALTMODE_FORCE_LSR	BIT(23)
#define PMC_USB_ALTMODE_CABLE_SPD(_s_)	(((_s_) & GENMASK(2, 0)) << 25)
#define   PMC_USB_ALTMODE_CABLE_USB31	1
#define   PMC_USB_ALTMODE_CABLE_10GPS	2
#define   PMC_USB_ALTMODE_CABLE_20GPS	3
#define PMC_USB_ALTMODE_TBT_GEN(_g_)	(((_g_) & GENMASK(1, 0)) << 28)

/* Display HPD Request bits */
#define PMC_USB_DP_HPD_IRQ		BIT(5)
#define PMC_USB_DP_HPD_LVL		BIT(6)

struct pmc_usb;

struct pmc_usb_port {
	int num;
	struct pmc_usb *pmc;
	struct typec_mux *typec_mux;
	struct typec_switch *typec_sw;
	struct usb_role_switch *usb_sw;

	enum typec_orientation orientation;
	enum usb_role role;

	u8 usb2_port;
	u8 usb3_port;
};

struct pmc_usb {
	u8 num_ports;
	struct device *dev;
	struct pmc_usb_port *port;
};

static int pmc_usb_command(struct pmc_usb_port *port, u8 *msg, u32 len)
{
	u8 response[4];

	/*
	 * Error bit will always be 0 with the USBC command.
	 * Status can be checked from the response message.
	 */
	intel_pmc_ipc_command(PMC_USBC_CMD, 0, msg, len,
			      (void *)response, 1);

	if (response[2]) {
		if (response[2] & BIT(1))
			return -EIO;
		return -EBUSY;
	}

	return 0;
}

static int
pmc_usb_mux_dp_hpd(struct pmc_usb_port *port, struct typec_mux_state *state)
{
	struct typec_displayport_data *data = state->data;
	u8 msg[2] = { };

	msg[0] = PMC_USB_DP_HPD;
	msg[0] |= port->usb3_port << PMC_USB_MSG_USB3_PORT_SHIFT;

	msg[1] = PMC_USB_DP_HPD_IRQ;

	if (data->status & DP_STATUS_HPD_STATE)
		msg[1] |= PMC_USB_DP_HPD_LVL;

	return pmc_usb_command(port, msg, sizeof(msg));
}

static int
pmc_usb_mux_dp(struct pmc_usb_port *port, struct typec_mux_state *state)
{
	struct typec_displayport_data *data = state->data;
	struct altmode_req req = { };

	if (data->status & DP_STATUS_IRQ_HPD)
		return pmc_usb_mux_dp_hpd(port, state);

	req.usage = PMC_USB_ALT_MODE;
	req.usage |= port->usb3_port << PMC_USB_MSG_USB3_PORT_SHIFT;
	req.mode_type = PMC_USB_MODE_TYPE_DP << PMC_USB_MODE_TYPE_SHIFT;

	req.mode_data = (port->orientation - 1) << PMC_USB_ALTMODE_ORI_SHIFT;
	req.mode_data |= (port->role - 1) << PMC_USB_ALTMODE_UFP_SHIFT;
	req.mode_data |= (port->orientation - 1) << PMC_USB_ALTMODE_ORI_AUX_SHIFT;
	req.mode_data |= (port->orientation - 1) << PMC_USB_ALTMODE_ORI_HSL_SHIFT;

	req.mode_data |= (state->mode - TYPEC_STATE_MODAL) <<
			 PMC_USB_ALTMODE_DP_MODE_SHIFT;

	return pmc_usb_command(port, (void *)&req, sizeof(req));
}

static int
pmc_usb_mux_tbt(struct pmc_usb_port *port, struct typec_mux_state *state)
{
	struct typec_thunderbolt_data *data = state->data;
	u8 cable_speed = TBT_CABLE_SPEED(data->cable_mode);
	struct altmode_req req = { };

	req.usage = PMC_USB_ALT_MODE;
	req.usage |= port->usb3_port << PMC_USB_MSG_USB3_PORT_SHIFT;
	req.mode_type = PMC_USB_MODE_TYPE_TBT << PMC_USB_MODE_TYPE_SHIFT;

	req.mode_data = (port->orientation - 1) << PMC_USB_ALTMODE_ORI_SHIFT;
	req.mode_data |= (port->role - 1) << PMC_USB_ALTMODE_UFP_SHIFT;
	req.mode_data |= (port->orientation - 1) << PMC_USB_ALTMODE_ORI_AUX_SHIFT;
	req.mode_data |= (port->orientation - 1) << PMC_USB_ALTMODE_ORI_HSL_SHIFT;

	if (TBT_ADAPTER(data->device_mode) == TBT_ADAPTER_TBT3)
		req.mode_data |= PMC_USB_ALTMODE_TBT_TYPE;

	if (data->cable_mode & TBT_CABLE_OPTICAL)
		req.mode_data |= PMC_USB_ALTMODE_CABLE_TYPE;

	if (data->cable_mode & TBT_CABLE_LINK_TRAINING)
		req.mode_data |= PMC_USB_ALTMODE_ACTIVE_LINK;

	if (data->enter_vdo & TBT_ENTER_MODE_ACTIVE_CABLE)
		req.mode_data |= PMC_USB_ALTMODE_ACTIVE_CABLE;

	req.mode_data |= PMC_USB_ALTMODE_CABLE_SPD(cable_speed);

	return pmc_usb_command(port, (void *)&req, sizeof(req));
}

static int pmc_usb_mux_safe_state(struct pmc_usb_port *port)
{
	u8 msg;

	msg = PMC_USB_SAFE_MODE;
	msg |= port->usb3_port << PMC_USB_MSG_USB3_PORT_SHIFT;

	return pmc_usb_command(port, &msg, sizeof(msg));
}

static int pmc_usb_connect(struct pmc_usb_port *port)
{
	u8 msg[2];

	msg[0] = PMC_USB_CONNECT;
	msg[0] |= port->usb3_port << PMC_USB_MSG_USB3_PORT_SHIFT;

	msg[1] = port->usb2_port << PMC_USB_MSG_USB2_PORT_SHIFT;
	msg[1] |= (port->orientation - 1) << PMC_USB_MSG_ORI_HSL_SHIFT;
	msg[1] |= (port->orientation - 1) << PMC_USB_MSG_ORI_AUX_SHIFT;

	return pmc_usb_command(port, msg, sizeof(msg));
}

static int pmc_usb_disconnect(struct pmc_usb_port *port)
{
	u8 msg[2];

	msg[0] = PMC_USB_DISCONNECT;
	msg[0] |= port->usb3_port << PMC_USB_MSG_USB3_PORT_SHIFT;

	msg[1] = port->usb2_port << PMC_USB_MSG_USB2_PORT_SHIFT;

	return pmc_usb_command(port, msg, sizeof(msg));
}

static int
pmc_usb_mux_set(struct typec_mux *mux, struct typec_mux_state *state)
{
	struct pmc_usb_port *port = typec_mux_get_drvdata(mux);

	if (!state->alt)
		return 0;

	if (state->mode == TYPEC_STATE_SAFE)
		return pmc_usb_mux_safe_state(port);

	switch (state->alt->svid) {
	case USB_TYPEC_TBT_SID:
		return pmc_usb_mux_tbt(port, state);
	case USB_TYPEC_DP_SID:
		return pmc_usb_mux_dp(port, state);
	}

	return -EOPNOTSUPP;
}

static int pmc_usb_set_orientation(struct typec_switch *sw,
				   enum typec_orientation orientation)
{
	struct pmc_usb_port *port = typec_switch_get_drvdata(sw);

	if (port->orientation == orientation)
		return 0;

	port->orientation = orientation;

	if (port->role) {
		if (orientation == TYPEC_ORIENTATION_NONE)
			return pmc_usb_disconnect(port);
		else
			return pmc_usb_connect(port);
	}

	return 0;
}

static int pmc_usb_set_role(struct usb_role_switch *sw, enum usb_role role)
{
	struct pmc_usb_port *port = usb_role_switch_get_drvdata(sw);

	if (port->role == role)
		return 0;

	port->role = role;

	if (port->orientation) {
		if (role == USB_ROLE_NONE)
			return pmc_usb_disconnect(port);
		else
			return pmc_usb_connect(port);
	}

	return 0;
}

static int pmc_usb_register_port(struct pmc_usb *pmc, int index,
				 struct fwnode_handle *fwnode)
{
	struct pmc_usb_port *port = &pmc->port[index];
	struct usb_role_switch_desc desc = { };
	struct typec_switch_desc sw_desc = { };
	struct typec_mux_desc mux_desc = { };
	int ret;

	ret = fwnode_property_read_u8(fwnode, "usb2-port", &port->usb2_port);
	if (ret)
		return ret;

	ret = fwnode_property_read_u8(fwnode, "usb3-port", &port->usb3_port);
	if (ret)
		return ret;

	port->num = index;
	port->pmc = pmc;

	sw_desc.fwnode = fwnode;
	sw_desc.drvdata = port;
	sw_desc.name = fwnode_get_name(fwnode);
	sw_desc.set = pmc_usb_set_orientation;

	port->typec_sw = typec_switch_register(pmc->dev, &sw_desc);
	if (IS_ERR(port->typec_sw))
		return PTR_ERR(port->typec_sw);

	mux_desc.fwnode = fwnode;
	mux_desc.drvdata = port;
	mux_desc.name = fwnode_get_name(fwnode);
	mux_desc.set = pmc_usb_mux_set;

	port->typec_mux = typec_mux_register(pmc->dev, &mux_desc);
	if (IS_ERR(port->typec_mux)) {
		ret = PTR_ERR(port->typec_mux);
		goto err_unregister_switch;
	}

	desc.fwnode = fwnode;
	desc.driver_data = port;
	desc.name = fwnode_get_name(fwnode);
	desc.set = pmc_usb_set_role;

	port->usb_sw = usb_role_switch_register(pmc->dev, &desc);
	if (IS_ERR(port->usb_sw)) {
		ret = PTR_ERR(port->usb_sw);
		goto err_unregister_mux;
	}

	return 0;

err_unregister_mux:
	typec_mux_unregister(port->typec_mux);

err_unregister_switch:
	typec_switch_unregister(port->typec_sw);

	return ret;
}

static int pmc_usb_probe(struct platform_device *pdev)
{
	struct fwnode_handle *fwnode = NULL;
	struct pmc_usb *pmc;
	int i = 0;
	int ret;

	pmc = devm_kzalloc(&pdev->dev, sizeof(*pmc), GFP_KERNEL);
	if (!pmc)
		return -ENOMEM;

	device_for_each_child_node(&pdev->dev, fwnode)
		pmc->num_ports++;

	pmc->port = devm_kcalloc(&pdev->dev, pmc->num_ports,
				 sizeof(struct pmc_usb_port), GFP_KERNEL);
	if (!pmc->port)
		return -ENOMEM;

	pmc->dev = &pdev->dev;

	/*
	 * For every physical USB connector (USB2 and USB3 combo) there is a
	 * child ACPI device node under the PMC mux ACPI device object.
	 */
	for (i = 0; i < pmc->num_ports; i++) {
		fwnode = device_get_next_child_node(pmc->dev, fwnode);
		if (!fwnode)
			break;

		ret = pmc_usb_register_port(pmc, i, fwnode);
		if (ret)
			goto err_remove_ports;
	}

	platform_set_drvdata(pdev, pmc);

	return 0;

err_remove_ports:
	for (i = 0; i < pmc->num_ports; i++) {
		typec_switch_unregister(pmc->port[i].typec_sw);
		typec_mux_unregister(pmc->port[i].typec_mux);
	}

	return ret;
}

static int pmc_usb_remove(struct platform_device *pdev)
{
	struct pmc_usb *pmc = platform_get_drvdata(pdev);
	int i;

	for (i = 0; i < pmc->num_ports; i++) {
		typec_switch_unregister(pmc->port[i].typec_sw);
		typec_mux_unregister(pmc->port[i].typec_mux);
	}

	return 0;
}

static const struct acpi_device_id pmc_usb_acpi_ids[] = {
	{ "INTC105C", },
	{ }
};
MODULE_DEVICE_TABLE(acpi, pmc_usb_acpi_ids);

static struct platform_driver pmc_usb_driver = {
	.driver = {
		.name = "intel_pmc_usb",
		.acpi_match_table = ACPI_PTR(pmc_usb_acpi_ids),
	},
	.probe = pmc_usb_probe,
	.remove = pmc_usb_remove,
};

module_platform_driver(pmc_usb_driver);

MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@linux.intel.com>");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Intel PMC USB mux control");
